Abstract:
Greenhouse and field experiments were carried out to determine the growth
performance of two banana cultivars inoculated with three AMF inocula under two
different soil conditions. A preliminary experiment (Inoculum potential trial) was
carried out to evaluate the potential of mycorrhizal inoculants and non-sterile soils
(controls) obtained from sites where the trial was to be established. This experiment
comprised three inoculants and two non-sterile field soils at three levels of the inoculant
(full dose, half dose and quarter dose). Greenhouse and field experiments comprised of
three types of inoculants (Kibungo mixed, Rubona mixed and single species Glomus
mosseae) and two soil substrates (Non-sterile soils from Kibungo and Rubona). Two
tissue cultured banana cultivars (Kamaramasenge and Mpologoma) were used for the
experiments. Plants were inoculated with AMF at weaning stage and 18 weeks later
transplanted to the field. Plant height, girth, leaf number, leaf length and width of the
youngest leaf were measured every two weeks for the greenhouse and field
experiments. Prior to field establsihment, root colonisation was assessed at planting and
in every subsequent month after transplanting. Results showed that mixed AMF from
Kibungo and Rubona were more infective than single species (Glomus mosseae) .The
controls (non-sterile soils) had a low infectivity which indicates that the banana
plantlets may be inoculated prior to establishment at these sites. In the greenhouse, the
effect of AMF inoculants on growth performance was dependent on the banana cultivar.
Kamaramasenge was not responsive to inoculation, it attained even higher growth
without inoculation. Under field conditions, inoculation significantly (P<O.05) enhanced
all parameters measured for Mpologoma cultivar at Kibungo and Rubona sites whereas,
inoculation had no significant (P>O.05) effect on growth of Kamaramasenge. The
growth of Mpologoma was however better at Rubona than at Kibungo. Non-inoculated
plants (Controls) had the least growth. The intensity of root colonisation was highest in
plantlets inoculated with mixed inoculants (AMF Kibungo and AMF Rubona)
compared to plantlets inoculated with single species inoculant (Glomus mosseae) and
plants in non-sterile soils from those sites (control K and control R). From the results, it
could be concluded that AMF have positive effects on the growth of banana plants.
There is need for further investigation on the efficacy of AMF to control pests and
diseases, and their effect on yields and drought tolerance in banana plants in Rwanda.
